The attachment of a door to a pillar, such as the A pillar of an automobile provides a good example of the applicability of the present invention. The A pillar is typically a hollow metal frame and the door is attached to the outside of the frame with a nut and a heavy elongated bolt which extends across the cavity of the hollow frame to prevent the opposed surfaces of the frame collapsing inwards. These elongated bolts are extremely heavy and so, undesirably, add to the weight of the vehicle. They are also expensive.
It is known to provide structural reinforcement in hollow structures by the provision of a core of reinforcing material coated with foamable adhesive material within the hollow structure. The foamable material is then activated by heat, typically the temperature in the drying oven of the e-coat anti-corrosion coating process so that it foams to fill the space between the core of reinforcing material and the hollow structure. The foamed adhesive material will also bond the core to the internal surface of the hollow structure. It has been proposed that such reinforcing structures may be used around positions of attachment but it has been necessary to ensure that the reinforcing structure be such that it allows for passage of the attaching means such as a bolt through the structure.